Last night we caught some of a BBC4 programme where Andrew Graham-Dixon talked about art in Tuscany in the late Middle Ages, particularly Giotto and Cimabue and the rise of the Franciscans. He made a very good case for nascent humanism in the images which the Franciscans used to engage with the working poor. In fact his argument was that the expressiveness in these paintings was more important for the main history of western art than the later discovery of perspective. I pulled out a book of his that I was given for Christmas a few years back about the 15th and 16th century art from the same part of the world and it was full of stuff that we had all been looking at in the past week. We flew out to Pisa from Gatwick early on Monday morning and flew back late on Friday evening.

Vita has decided she will study graphics in Falmouth for the next three years and the trip was primarily linked to this . James had visited Florence in his Grand Tour during his year out and Yvonne and I had visited the city separately in the 1970s. In fact I spend three weeks there working through in detail while my girlfriend of the time studied Italian. On the basis of this earlier visit I had always thought that the real highlights in Florence were mostly works created in the first half of the 15th century � their freshness, directness and human scale. Indeed we started there looking at the Ghiberti doors on the Baptistery.

James developed his taste for mannerism � the other end of business from the directness and apparent honesty of the quattrocento. He made sure that we looked at Pontormo�s Deposition in Santa Felicita, a church which you might otherwise ignore at the south end of the Ponte Vecchio. It was certainly well worth the effort to find it both in terms of its extraordinary treatment of its theme in colour and configuration but also in its setting � a church with an ancient history which had been restyled in the 15th century and then elaborated, probably in the 17th century. I could see this painting as a development of Michelangelo�s Holy Family in the Uffizi.

There�s a tremendous amount of hysteria and confusion involved in getting into the big name sites � the Uffizi and the Academia. Everyone seemed to think that it was worth the effort in the case of the Uffizi for the Botticelli�s alone - despite everything they really stand out. The Academia is more of a puzzle because the star piece is David and I am not at all clear what it means. I did an exercise while I was there looking at the faces of the people as they walked down the corridor towards the piece, looking to see whether there was any recognition of the sublime. I didn�t see any. In fact there is a modern artwork in the entrance hall on this theme � a photograph of tourists looking at the statue which doesn�t feature in the composition. In this photograph people do look overcome by the art � I think it must be posed which of course makes it a typically complex piece of photo-driven art from the last 10 years or so. AGD gives an account of David in terms of ambiguities and I guess I should read this carefully.

Still on the subject of Michelangelo, we visited his Laurentian Library next door to San Lorenzo, very close to where we were staying. This was truly astonishing, overwhelming and sublime, drawing one into its own world � supposedly a world of learning but one where the rational and irrational are closely intertwined, particularly in the details. James and I talked about the way that it symbolised the flawed ideals of academic excellence, prompted by overhearing a party of American students discussing the place with their professor which seemed to represent an alternative democratic ideal of learning.

Rational art is equally subject to critique next door in San Lorenzo. Brunelleschi was a favourite of mine, a discovery on my first visit. This time I felt that the church exemplified reason in the service of temporal power in the scale of its order and logic � it was built for the Medicis. Just the other side of San Lonrenzo the relationship between art and power is further questioned in a set of Medici tombs. The two better, smaller ones are by Micheleangelo but their occupants were apparently undistinguished and unpleasant.

So it is plutocracy in San Lorenzo but five minutes away opposite the still stunning modern rationalism of the railway station, quite innocent except for the fact it was commissioned during the fascist era, is Santa Maria Novella which is still Dominican and just full of wonders. One that I had missed the first time was Uccello�s flood, a fresco in a cloister. He uses the new science of perspective to express the drama and violence of the episode, a device that keeps its potency right into the 1960s pop art, like Wham.

Lingering is a question posed by Hannah Arendt and Andrew Feenberg's book on Marcuse. This is whether it is at all realistic to think that the aesthetic response, as analysed by Kant - the stuff I wrote about in the previous entry - whether this can really be the source of practical social motivation to make things better. When art does it stuff (graciously) then we are engaged and we move from the particular, the artwork itself, to the general and we shift from individual taste to engage others in our understanding and experience. But this is perhaps only ever a matter of consolation